Processes for treating soil, such as golf greens, are well known to those skilled in the art. Thus, by way of illustration, several United States patents have issued to William M. Benson of Martinez, Georgia. U.S. Pat. No. 5,433,759 describes a system for treating the soil and turf within a prescribed subsoil profile that includes heat exchanger means comprising a length of air conduit buried beneath the ground. U.S. Pat. No. 5,507,595 describes an apparatus for treating the soil of a grass playing field which includes separator means for removing water from an air stream moving between a blower and a piping system. U.S. Pat. No. 5,542,208 describes an apparatus for treating the soil of a sports field or grass site which includes a flow reversing means for reversing the flow of air through a duct network, comprising a four-way valve mounted upon a mobile unit. U.S. Pat. No. 5,596,836 describes a system for controlling the soil temperature of a grass playing field comprising a blower means having a suction port and a discharge port that is connectable to a duct network. U.S. Pat. No. 5,617,670 discloses an apparatus for treating the soil of a grass sports field that includes valve means operable for selectively connecting a drain line to a duct network, comprising a first valve and a second valve. The disclosure of each of these United States patents is hereby incorporated by reference into this specification.
A system similar to those described in the aforementioned United States is marketed under the name of SUBAIR by SubAir, Inc. Although this system has met with a moderate amount of commercial success, it has not achieved wide acceptance in the golf course industry. A substantial number of customers have complained that the use of such system often damages the drain tile underneath golf greens and damages the roots of the grass of the greens. When damage to the drain tile assemblies of the golf courses occur, the golf greens must be rebuilt, frequently at substantial expense and inconvenience.
Without wishing to be bound to any particular theory, applicants have observed that when the SUBAIR system is used when the ambient air is at least about 90 degrees Fahrenheit, the soil treated with the system is heated rather than cooled, often increasing in temperature by at least about 15 degrees. Similarly, when the SUBAIR system is used when the ambient air is at a temperature of less than about 45 degrees Fahrenheit, the soil treated with the system is cooled rather than heated. Under either of these conditions, the use of the SUBAIR system aggravates rather than remedies the problem it is designed to solve.
It is an object of this invention to provide a system for conditioning soil in which, even under conditions wherein the ambient air is at least about 90 degrees Fahrenheit, the soil will be cooled substantially.
It is another object of this invention to provide a system for conditioning soil in which, even under conditions wherein the ambient air is less than about 45 degrees Fahrenheit, the soil will be heated substantially.
It is yet another object of this invention to provide an improved apparatus for conditioning soil.